Note: Descriptions are shown in the official language in which they were submitted.
123~32~
PHYLA) (OF Tile INVENTION
Jo
This invention relates to a tabulated composition comprising an
~-halog2nated disinfecting agent and a borax binder, and to a method
of treating water with said tabulated composition. More specifically,
this invention relates to a tablet comprising on a weight basis from
about 40 to about OWE of an N-nalogenated hydantoin and from about 5
to about 60% borax binder, said tablet having a break strength of at
least 35 pounds as determined by a Remake Spring ester, and a density
of between about 1.5 to 2.0 gm./c~. lost specifically the invention
relates to the tabulated composition defined above suitable for use in
a toilet tank dispenser of thy type wherein a disinfectant solution is
dispensed each time the toilet tank is leeched, and to a method of
disinfecting.
AWAKENED OLD INVENT
'he germicidal and disinfecting activity OX N-halogenated organic
compounds, particularly N-halogenated hydantoin compounds, is well
known. Us Patent 2,~8,7~4 to Blomfield discloses an improved
bleach composition containing dichlorodimethylhydantoin in combination
with an alcoholizing agent, e.g., alkali metal hydroxides and
silicates. US. Patent 3,318,815 to l~emler, et at., discloses a
toilet bowl cleaning composition having germicidal properties,
particular germicides being l-chloro- and 1,3-dichloro-5,5-dimethyl-
hydantoins. The Reeler, et at., composition contains less than I of
the germicide, and are granulated compositions for pouring into the
toilet jowl. similarly, US. Patent 8,~7 to lodes discloses an
iodinated deterrent used in the' form of a dilute solution, as a hard
surface cleaner.
Us Patent 3,147,214 to Paterson discloses ~-halogenated
organic suitable ion use as disinfectants for swimming pools, the
disinfectants including hydantoins, provided in tablet form as
indicated in example 1 thereof. However, the tablets contained no
'binder, and were dissolved rapidly. As pointed out in US. Patent
3,412,021, also to Paterson, the compositions of the '219 patent were
restricted to sin~le-dosage.uses because of the difficulty in metering
available halogen. The '021 patent discloses that this metering
0544H - 2 -
.'.~,,
123~82~
problem may ye overcome by using a low-solubility disinfectant, for
example, bromochlo~o~imethylhydantoin, in agglomerate form, the binder
being selected Loom polymers, for example, natural an synthetic
rubbers, the polyisobutylenes, the polystyrene, and the like, and
from polyvalent metallic cations, for example, those of aluminum,
zinc, tin, iron, chromium, magnesium and silicon.
Louvre, the Paterson agglomerates are of low density and are
extremely friable. pence, because of their porosity, small
extradites, cakes and tablets containing large amounts of disinfectant
are not achievable. Furthermore, integrity is poor, resulting in
extradites, tablets and cakes that crack, chip, and break during
manufacture and handling. Finally, the Paterson '021 agglomerates,
because of the low density and friability, have a dust problem, which
requires special consideration during manufacture to reduce both
health and safety dangers. rusting also presents a problem when the
agglomerate is to be placed within a two piece plastic container,
which container is sealed by heat or radio frequency sealing.
US. Patent 4,297,224 to Macchiarolo, et at., discloses a method
for the control of buffaloing in recirculating water systems, the
method utilizing both non oxidizing and oxidizing besides. With
respect to the hydantoin disinfectant recited in the '224 patent, the
agglomerates of Paterson are used. Similarly, US. Patent 4,058,618
to Ovchinnikov, et at., discloses the efficacy of dichlorodimethyl and
dimethylhydantoins in combination with one another. The Ovchinnikov,
et at., composition also comprises an anionic surfactant, a phosphate
detergent builder, and sodium chloride and sodium sulfate as delineates
to prevent self-heating.
Us Patents 4,308,62$, 4,249,~74, 4,248,827, and 4,200,606, all
to Kitko, and 4,216,027 to Wages, each disclose generally various
N-organic disinfectants for use in a toilet bowl dispenser. US.
Patent 4,281,421 discloses a hypochlorite cake in the form of a
syllable matrix of limited volubility, the cake comprising the
hypochlorite disinfecting agent, and a water-soluble salt of a
metasilicate, carbonate and orthosilicate anion, there being at least
one cation present that forms an insoluble salt of said anion.
0544H _ 3 _
US
No references are known which use borax as a binder for the
N-halogenated compounds of the present invention. However, US.
Patent 3,883,303 to Roberts discloses a granular composition of borax
and paraformaldehyde to treat septic tanks by adding said composition
to the toilet bowl. The borax adjusts the pi of the water to optimize
paraformaldehyde volubility. US. 4,110,431 Jo Cite discloses a wet
weather resistant binder composition comprising a water-soluble
polymer and borax, the binder being admixed with a powdered pesticide
to promote adherence thereof to foliage. US. Patent 3,767,586 to
Rutkiewic discloses stable concentrated aqueous solutions of N-halo
compounds with borate salts as a weak buffer, while US. Patent
2,121,501 to ~ershman discloses a borax-containing calcium
hypocblorite composition, wherein borax is an optional cleaner
constituent. Calcium hypochlorite cakes are disclosed in Us Patent
3,793,216 to Dychdala, wherein a hydrated inorganic salt, for example,
, borax pentahydrate, is incorporated, the concentration thereof being
at least 42% by weight, and US. Patent 3,406,116 to Vital disclosed
N-chloro hydantoins in a granulated abrasive cleaner composition,
borate being optionally includable as an adjutant.
None of the references cited above, however, considers the'
problems of providing tablets of N-halogenated hydantoins that do not
chip, crack or break, that can be manufactured with a high ratio of
i active disinfectant to tablet volume, or that minimize the problems of
dust generation during manufacture, shipment and handling.
SEYMOUR OF INVENTION
, ___ ...... .. , ,,, ___
The tablets of the present invention comprise on a weight basis
from about 40 to about 95% of an N-halogenated hydantoin disinfectant
i compound, from about 5 to about 60% borax binder, and from about O to
10 of a lubricant, the tablets having a break strength of at least 35
pounds on a Remake spring Tester. The tablets are substantially dust
t free and resist breaking, capping and fracturing during normal
handling. In water the tablets retain the tabulated configuration for
prolonged periods of time, that is for about two to six weeks, when
included within a toilet bowl dispenser herein described. Preferably,
the tablets comprise between about 20 to 45% by weight borax, and
! between about 50 to 80% hydantoin. Most preferably, the tablets
0544H _ 4 _
I:-
. . Jo `.
, -I,,; -
82~
comprise 25 to 35% borax and 60 to 75% by weight hydantoin. A
lubricant is preferred in a preferred amount of from 0.25 to 5%
to facilitate release of the -tablet from the tablet press.
The present invention also relates to a dispenser adapted to
contain the tablet, the dispenser in general -terms comprising a
receptacle for the tablet having a water inlet, a solution outlet,
and an air vent. Preferred embodiments of the dispenser comprise
a solution reservoir having a lower portion and an upper portion,
the volume of solution in the upper portion being dispensed by
flow through an inlet/discharge conduit adapted to provide siphon
or siphon/gravimetric flow of liquid from the reservoir. In the
preferred embodiment, the tablet is retained in the upper portion
of the reservoir.
In one embodiment the present invention provides such a
disinfectant composition comprising on a weight basis:
(a) from about 40 to 95~ of an N-halogenated
hydantoin disinfectant selected from the
group consisting of 1,3-dichloro-5,5-dimethyl-
hydantoin; 1,3-dibromo-5,5-dimethylhydantoin;
l-bromo-3-chloro-5,5-dimethylhydantoin, and
combinations of same,
(b) from about 5 to about 60~ of a borax binder,
(c) from about 0.25 to about 5.0% of a lubricant, and
(d) less than about I free water moisture,
said tablet having a break strength of from about 35 to about 100
pounds as measured on a Remake Spring Tester, and a density of
from about 1.5 to about 2.0 gm./cc.
In another embodiment the invention provides a method of
disinfecting water comprising the steps of providing 2 disinfectant
- 5 -
~23~8~:S
tablet in a container, said tablet comprising on a weight basis
from about 40 to 95% of an N-halogenated hydantoin disinfectant;
from about 5 to 60~ borax binder; less than 10~ lubricant, and
less than I water moisture, said tablet having a break strength
of at least 35 pounds on a Remake Spring Tester and a density of
from about 1.5 to about 2.0 gm./cc.; contacting said tablet in
said container with water to dissolve a portion of said tablet,
and dispensing the resulting solution into the water to be treated.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is one embodiment of a dispenser of the present in-
mention containing the tablets of the present invention.
Fig. 2 is a second embodiment of a dispenser of the present
invention wherein the tablet is contained in an upper portion
of the dispenser solution reservoir.
Fig. 3 is another embodiment wherein two dispensing chambers
are provided in tandem, one dispensing chamber containing a
surfactant solution, the other chamber containing the disinfectant
tablet disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
.
The composition of the present invention, which comprises,
in tablet form, an N-halogenated hydantoin disinfecting agent
and a borax binder, is suitable for use as a water-treating and
disinfecting material of general application wherein the tablet
is provided in a container, water is brought into contact with
the tablet to form a concentrated disinfectant solution, and said
solution is released into the body of water to be treated. Hence,
; so
.
I
the tabulated composition of the present invention has utility
in the treatment of water in swimming pools, industrial process
water, ponds, fountains, and the like where a small portion of
the water, either as make-up or from the total volume of water
present, is circulated continuously through the container and
past the tablet of the present invention.
In particular, the tablet can be provided in a container,
i.e., a dispenser, for insertion into a small body of water, for
example, in a toilet tank, a concentrated solution of the
hydantoin disinfecting agent being formed within the container
upon filling of the tank after a flush, the concentrated solution
being discharged into the tank water, and, ultimately, into the
toilet bowl, each time the tank is flushed.
Although agglomerates - i.e., cakes, extrudants and tablets -
of N-halogenated hydantoins are known, specifically, those of
Paterson, So Patent 3,412,021, prior art products are severely
limited in application. The agglomerates of Paterson are quite
friable, and result in products of poor integrity. Tablets of
Paterson are apt to break, crack or chip during manufacture and
handling. This is disadvantageous where one or two tablets are
to be provided in a dispenser, e.g., a toilet tank dispenser, in
that less than a whole tablet may sometimes be placed in the disk
penner, said dispenser then not containing the requisite amount
of disinfectant material. Where many tablets are to be placed
in a container, i.e., in swimming pool water treating devices,
it is undesirable to have tablets of varying size because disk
solution will vary in proportion to the surface area exposed.
Perhaps more importantly, severe breakage results in a large
volume of powder, which is usually discarded as waste.
In addition, the prior art agglomerates tend to disintegrate
rapidly, which rapid disintegration is highly undesirable where
a single tablet is to last for long periods of time. This problem
is particularly acute in toilet tank dispensers where the
hydantoin disinfectant tablet should retain its configuration for
~q~3~
two to six weeks, depending on the level of use.
Moreover, the prior art agglomerates are porous, having a
very low density. To incorporate a given volume of disinfectant
material into a dispenser provided with one or two tablets no-
quirks a large container or dispensing chamber, which size is
often limited by the tank in which the dispenser is placed. For
example, a toilet tank is of limited size and contains various
piping and valves. A toilet tank dispenser must be of such size
as not to interfere with the proper operation of the valves.
Hence, it is necessary to use a tablet of high density providing
the requisite amount of disinfecting agent, a problem not addressed
by the prior art.
Finally, the tablets should be substantially dust free to
minimize problems during manufacture of the tablet and during
subsequent use, especially during subsequent incorporation of the
tablet into a dispensing container. In particular the problem of
dusting is acute where the dispensing container is of two piece
plastic construction, the two pieces being joined together by
heat or radio frequency sealing. The prior art hydantoin Anglo-
morales are quite dusty in view of their porosity and friability
and require suitable precautions during manufacture, shipment
and handling.
The tablets of the present invention overcome each of the
problems associated with the prior art product. The present
invention provides tablets that:
(a) are substantially dust free;
(b) have a minimum break strength of 35 pounds
on a Remake Spring Tester, and therefore resist
breaking, chipping or fracturing during normal
shipment and handling;
(c) have a density of from 1.5 to 2.0 gm.~cc., and
hence contain a large amount of the disinfectant
,
- pa -
~3~32~
in tablets of small volume not withstanding
the binder concentration
(d) have a high break strength permitting flexibility
as to tablet size and dimensions;
(e) have dissolution characteristics which can be
regulated by varying the proportions of the
constituents and by regulating density, and
which are
` - 7b -
adapted to retain the tablet configuration in
solution over long periods of time;
(f) resist "capping", that is the tendency of the planer
surfaces to shear from the body of the tablet, and
"lamination", the tendency of a tablet to break along
~tLia in the Dozy of the tablet, and
(g) can be fabricated on a commercial tabulating press.
'the Tablet
The composition of the present invention comprises on a weight
basis from about 40 to about 95% of an N-halogenated hydantoin and
from about 5 to about OWE borax binder, said tablet having a break
strength ox at least 35 pounds as determined on a Remake Spring Tester,
described below in treater detail. Preferably, the tablet further may
optionally contain from about 0.~5 to about 10% of a lubricant to
facilitate release of the tablet from the die. Lyon materials are
known in the art of tabulating which can be used for this purpose,
although fatty acids of I to I carbons and their alkali metal salts
are preferred in that they are not readily oxidizable by the hydantoin
disinfectant. Preferred lubricar-t4 are Starkey acid and sodium
Stewart.
The tablet also contains water associated with the borax, if any,
and may also contain free water, that is, water not bound to the borax
binder. Various impurities, up to about Lowe my weight, or example,
alkali and alkaline earth metal halogen salts appearing as by-products
in the hydantoin manufacture may also eye present. Preferably, the
free water is less than about 3% by weigh:, while the impurities are
preferably less than about OWE by weight.
though borax is the sole binder Loud which provides tablets of
the requisite properties, it should be understood that the impurities
mentioned above may have a positive effect on the integrity of the
tablet. However, as described below, these impurities as binders do
not provide the desired tablet characteristics unless admixed with
borax according to the presort invention. Finally, other materials
used as binders in the tabulating art, while not worming satisfactory
0544H _ _
,
lZ308~
tablets with hydantoin, may not deleteriously affect the tablet of the
preset invention. It is not intended that the novel benefits derived
from the tabulating of hydantoins with borax be restricted by tube
presence in minor amounts of other constituents. That is, the present
invention is to be construed broadly as the tabulating of hydantoins
with borax, which provides highly desired properties to tube tablet not
achieved in its absence.
The hydantoin compounds preferred or incorporation in tube
tablets of the present invention are 1,3-dichloro-5,5-dimethyl-
hydantoin; 1,3-dibromo-S,5-dimethylhydantoin, and 1-bromo-3-chloro-
5,5-dimethylhydantoin. Preferably, the hydantoin is present in the
range of from about 50 to about 80% by weight of the tablet, most
preferably from about 60 to about 75% by weight. Although the
pentahydrate form of borax, Nub, is preferred, other
forms, including an hydrous borax, can be used. An hydrous borax is
hydroscopic and will absorb free water in the composition, or
atmospheric moisture, to provide a hydrate. The borax is present
preferably in the range of from 20 to about 45% by weight, most
preferably from about 25 to about 35V~ by weight. The borax may be
granular or puffed, both being commercial forms of borax. Puffed
borax has a density of from 8 to about 50 lbs./ft.3, and it
described, for example, in US. Patent 3,994,651 to D'Souza.
Granular borax, which has a
bulk density of about 50 to 70 lbs./ft.3, it preferred.
The tablets can be made with conventional tabulating equipment,
for example, Stokes-Penwalt rotary press yodel No. DDS-2, by feeding
an intimate mixture of the composition described above to the die.
Line speeds may be up to 300 tablets per minute, preferably from about
30 to about 200 tablets per minute, with pressure. of from stout 2
tons to about 20 tons, depending upon the percent binder, and desired
density and hardness of the tablet. Operation of the tabulating press
to obtain the tablets of the present invention Jay require preliminary
trials to establish specific operating conditions for given tablet
properties. However, suck trials are well within the ordinary isle
of one practicing the tabulating art.
In the search for a binder that would provide hydantoin tablets
wit the desired properties of hardness, density, and integrity, both
0544H _ g _
..,~
~23082~:;
when dry and when immersed in water, many substances were considered.
Such conventional binders as starch, cellulosic materials, albumin,
gelatin, and the like were dismissed because of potential oxidation of
the binder by the hydantoin. During manufacture the probability of an
exothermic reaction-exists with these materials, and their use is
considered unsafe. similarly, other organic compounds with oxidizable
sites are considered incompatible with hydantoin, a strong oxidizing
agent.
Such incompatibility also exists with many inorganic compounds
conventionally used as a binder in the tabulating art, especially at
the pressures under which the tablet press operates. Even if the
reaction is minimal, tube evolution of gases during tabulating prevents
an undesirable condition. Furthermore, the generation of even small
amounts of gas compromises tablet integrity. Finally, the binder
selected must be compatible with the hydantoin disinfectant when the
tablet is immersed in water.
Hard tablets were made on a Carver Lab press with between about
i 35 to I by weight sodium bullfight and sodium sulfate at 10 tons
I pressure, but reacted when immersed in water. Tablets
I made with 30 to 40~/0 by weight sodium metasilicate on a Carver Lab
¦ press disintegrated in water after two minutes. Similar
disintegration occurred with tablets containing 30% by weight of
! sodium carbonate, sodium bicarbonate, and potassium bromide.
i Tablets made on a Carver press with 5, 20 and 35% calcium
carbonate and 5, 20 and 35b sodium chloride were also unsatisfactory.
The calcium carbonate tablets ranged from soft to hard, and were prone
to cap and/or flake during handling. Tablets with 35% sodium chloride
were hard, but disintegrated in water; I Nail tablets typically were
soft, yet did not readily dissolve when immersed; 20% tablets provided
tablets that were of moderate hardness and stability. However, all
Nail tablets were prone to cap and/or flake. Furthermore, Nail at all
concentrations tended to leach out in water over time, leaving a
hydantoin skeleton that disintegrated. None of the binders referred
to above was found to provide a tablet of the desired properties.
Initial trials with borax indicated that hard tablets could be -
made with a minor degree of zapping. It was also found that a tablet
0544H - 10 -
~Z3~)82S
made on a Carver lab press comprising by weight vow puffed borax
(I lb./ft.3), 10% magnesium nitrate hexahydrate, 64%
dibromoclimethylhy(lantoill, and it water moisture was relatively stable
in water. This tablet was placed in a toilet bowl, Wesley teas flushed
10 times over a four-hour period. The borax-containing tablet
retained its integrity even under this dynamic testing. other tablets
containing borax and magnesium nitrate were unacceptable, however, in
view of poor integrity, and magnesium nitrate was eliminated as a
critical constituent.
Tablets containing borax alone were prepared on a carver lab
press at 5, lo 15, 20 and 35% borax. These tablets had break
strengths ranging from about 32 lobs. (Remake Spring Tester) for a 5% by
weight puffed borax lo lb./ft.3) tablet to over 100 pounds,
depending upon the pressure applied in the press and the dwell time in
the die to allow air to escape. Other such tablets containing 5%
borax had break strengths of from 40 to 55 lobs. Capping for most of
these tablets was slight tug moderate.
It was also observed that borax tended to be leached from the
tablet slowly when immersed, producing a honeycombed tablet but which,
unlike sodium chloride, retained its tabulated configuration. This
unexpected attribute of borax tabulated hydantoin tablets is
-preferred, in that a greater surface area of the hydantoin
disinfectant is provided after a short period of time in water, and
increases the delivery rate of hydantoin, a material of limited
volubility, without disintegration of the tablet itself. It is
believed that the volubility of the borax is such that removal of this
binder does not occur when the tablet is placed in water. Conversely,
it is believed that materials having a high volubility, e.g., sodium
chloride, are removed from the tablet far more quickly than the
depletion of hydantoin. For a binder to be acceptable, it must not
only provide the tablet properties desired, but must remain in
sufficient quantity to maintain the tabulated configuration over the
life of the hydantoin disinfectant. When used in a toilet tank
dispenser, the tablet should retain its shape typically for about two
weeks to about six weeks, depending on the level of use of the
dispenser.
..
0544H - if -
. -
;
~2308Z5
In addition to the materials mentioned above, boric acid tablets were jade in a con~erci~l tabulating press. These tablets contained
20 and owe boric acid. oily ox the boric acid tablets provided the
integrity required, with break strengths substantially Boyle the
requisite of 35 pounds on a ~imac Spring jester.
In addition to the physical attributes of the tablets, an
important consideration in the selection of the binder is ease of
tabulating in a commercial press. borax was found to be quite
suitable for use in commercial tabulating machines, with a minimum of
sticking to the die. Use of a lubricant, however, was found to
facilitate removal of the tablets. Sodium Stewart and Starkey acid
are preferred lubricants in that these materials do not have readily
oxidizable moieties.
With borax as the binder, the tablets of the present invention
resist "capping," that is, the tendency of the planar surfaces to
shear from the body of the tablet. zapping occurs because the planar
surfaces are not compressed to the same degree as the central core of
the tablet during manufacture. We have found that borax is superior
to other binders in forming tablets that provide the requisite brisk
strength at the densities stated, and with a minimum of capping.
Capping is disadvantageous because the "cap" is likely to form
particulate waste that requires disposal, and because the body of the
tablet remaining is more easily broken during shipment and handling.
~`urthecmore, capping can decrease the total weight of the tablet by as
much as owe typically 5 to 15%, which compromises quality control of
products incorporating the tablet.
The tablets of the present invention have a break strength, as
previously mentioned, of at least 35 pounds, as measured on a Remake
Spring Tester. In this test the tablet is placed on edge between two
opposed flat plates and a force applied to the tablet until the tablet
jails. 'rho lilac Spring Tester is manufactured by Rinck-McIlwaine
ha. of ~umont, Jew Jersey, and is a conventional method of
ascertaining break strength. Preferably, the tablets have a break
strength of from So to about 100 pounds.
Advantageously, the tablets of the present invention have a
density of from about 1.5 to about 2.0 gm./cc., preferably from about
4 - 12 -
.
___
I
1.55 to about I grll./cc. Notwithstanding high borax concentrations,
these tablets have a high ratio of disinfectant to volume, which is
desirable when the end product is a container of limited size for
immersion in a small body of water. At these densities, the tablets
dissolve gradually over time, and are suitable for use in a toilet
tank dispenser having a useful life, depending on the level of use, of
from 15 to 45 days or longer. of course, near the end of the life of
the tablet, the tablet is weakened by the depletion of materials, and
may crumble.
The Dispenser
'he toilet bowl dispenser into which the tablet may be placed
comprises in most general terms a receptacle containing the tablet,
said receptacle having a water inlet, a concentrated disinfectant
solution outlet, and an air vent provided in the top of the receptacle.
A preferred embodiment of a dispenser suitable for use in the
toilet tank with the tablet of the present invention therein is shown
in Fig. 1.
,
'Lowe dispenser I of Fig. 1 comprises a solution reservoir 11
having a lower portion 12 for containing the tablet 13 and an upper
portion 15 whose volume is equal to the amount of disinfectant
solution dispenses. A shoulder 16 is formed at the interface between
the lower and upper portions, a siphon inlet/discharge conduit 20
extending upwardly from said shoulder. The conduit 20 comprises an
exterior leg I that extends below the shoulder 16, said leg 21 having
an inlet/outlet port 22 proximate the bottom thereof, and an interior
, leg 23 extending upwardly from the shoulder 16. eye legs 21 and 23
meet in at the arcuate portion I preferably at the level of the top
17 of the dispenser 10. The water the height of the interior leg
23, the less is the amount of diffusion or migration of concentrated
disinfectant solution from the solution reservoir 11 during static
conditions. 'rho top of conduit 20 may, however, be within the range
of the height of the shoulder I and the top 17 of the dispenser 10.
Vent 27 extends prom the top 17 of the dispenser, and is in
communication with the atmosphere when the dispenser is in position in
the toilet tank. I-
0544H - 13 -
:
~Z308~S
The dispenser 10 works on the principle of siphon, or on a
combination of siphon and gravity discharge, depending upon the height
of the conduit 20. thus, with the conduit 20 at the height of the top
17, all of the solution in the upper portion 15 is dispensed by siphon
flow. When the level of the solution reaches the shoulder 16, and air
entering through vent 27 enters conduit 20, flow from the dispenser 10
terminates. Conversely, with the top the conduit 20 at a point
between the top 17 and the shoulder 16, that portion of the solution
above the top of the conduit 20 discharges by gravity flow, while the
portion below the top of the conduit discharges by siphon flow.
Fig. 2 illustrates a most preferred embodiment of the dispenser
of the present invention. In this embodiment the solution reservoir
45 of the dispenser 50 comprises an upper portion 51 and a lower
Jo portion 52, the shoulder 53 being formed at their intersection. The
conduit 20 extends from the shoulder as described above with respect
!, to the embodiment of Fig. 1. Similarly, the vent 27 extends from the
E top 17 of the dispenser 50.
In this embodiment a shelf 55 is provided between the upper and
, lower portions ox the solution reservoir, the shelf projecting '
f partially into the dispenser such that an elongate pathway 56 it
formed between the shelf and the back wall 57 of the dispenser 50.
The disinfectant tablet 13 is provided in the upper portion 51.
This location of the disinfectant cake is preferred because a
ore concentrated solution is dispensed. It is believed that a
I
concentration gradient exists within the dispenser, the disinfectant
solute having a tendency to gradually settle towards the bottom. With
the tablet in the lower section', the solution dispensed is the solute
, lean liquid in the upper portion as admixed during dispensation with
i the solute rich liquid in the lower portion. With the tablet in the
upper portion, the solute rich liquid is in the upper portion of tube
i chamber.
Fig. 3 illustrates a dispenser 70 having a first section 74
comprising the dispenser 10 of Fig. 1 and a second section 84
comprising the dispenser 50 of Fig. 1, said dispenser 70 being
i fabricated from a first suet of plastic thermoformed Jo provide the
upper and lower portions 75, 76, 85 and 86, the conduits 77 and 87f'
0544H - 14 -
I 3
and the vents 78 and 88, and a second jacking sheet of plastic (not
shown) affixed to the first sheet by radio frequency sealing. In ibis
embodiment, the tablet of the present invention is provided in upper
portion 85 of section 84, while a detergent cave, known in tube art, is
provided in the lower portion 76 of section 74. Wren placed in the
toilet tank, both disinfectant and detergent solution are released to
the bowl water. Known surfactant cakes suitable for use in the dual
chamber dispenser of the present invention are disclosed in US.
Patent 4,216,027 to Wages.
The dispenser of the present invention is adapted to deliver
preferably between 10 and 100 ml. of concentrated solution of
disinfectant such that the concentration of disinfectant in the bowl
after the flush is between 2 and 15 Pam., for between 15 to 45 days or
longer based on an average use of 10 to 20 flushes per day. To
achieve this level of disinfectant concentration in the bowl water,
the tablet should contain between about 10 to 50 grams of the
disinfectant. Conveniently, the tablet is between 3/4 to 1-3/4 inch
in diameter and from 3/8 to 1-1/4 inches high. however, these
dimensions are not critical. The dispenser can easily be fabricated
in plastic by thermoforming to suitable dimensions that fit within
most toilet tanks.
EXAMPLE I
Tablets were made on a Stokes-Penwalt DS-3 fourteen station ten
ton rotary ablating press using a 1 inch diameter straight walled
die. The tablets were made with bromochlorodimethylhydantoin and
either 20 lb./cu. ft. or 40.lb./cu. ft. puffed borax. The tablets had
a moisture content of from about 1 to about 3% by weight. Three
tablets from each run were weighted, measured for size, and tested for
break strength after aging for at least 24 hours. The averages of the
readings are provided below in Table I. In run no. 8, the tablet also
contained 3 calcium chloride.
0544H - 15 -
I
Table 1
Average Average Average
Borax Tablet tablet wreak
I Run density Borax Watkins Strength
No.(lb./~t.3) (wt. my (cm (lobs.
1 20 10 ~.53 1.0~ 65
2 20 20 7.68 1.17 23
3 40 10 9.18 1.13 57
4 40 10 9.10 1.15 53
9.43 1.20 55
6 40 20 9.~2 1.10 71
7 40 30 10.73 1.20 76
8 40 10 9.76 lo 15 55
Wit respect to run no. 2, the low break strength it attributable
to the low density of the tablet, calculated as 1.3 gag Each of
¦ the other runs, nos. 1 and 3 to 8 provided tablets with densities
ranging from 1.55 to 1.76 gag
¦ Overall tablet integrity (dry) was varied from very slighti capping (run no. 6) to moderate capping (run nos. 1 end 8). The,
¦ latter two runs had a relatively low ratio of binder to disinfectant.
EXAMPLE II
Tablets were made with bromochlorodimethylhydantoin on a Stokes-
Penlight single station press using a 1 inch tapered die, and are
reported in Table II. The feed mixture contained 68~ hydantoin, 31%
granular borax and I sodium Stewart
,
!
0544~ - 16 -
3L23~32~
ruble II
Break Tablet
Hun Force Tablets/ Wt.Thickness strength Density
No . tons minute m. inn . ) (1bs . )
1 < 2 15 10. 50. 532 10 1. 53
2 2 15 10 . 65). 515 30 1. 60
3 4 15 10 . 30. 483 45 1. 66
4 6 15 I().6().480 95 1.71
6 20 10. 50.475 70 1. 71
6 6 30 10 . I . 485 42 1 . 69
7 8 - 10 . 10 . 455 80 1 . 72
Tablet integrity was good, with slight capping. Tube tablets had
shiny sides, and did not stick to the die or punch. The tablets of
run no. 6 had slight lamination marks. With respect to run no. 1, it
is believed that the force applied was insufficient to obtain tablets
of high break strength.
Tablets were made as above with 78% bromochlorohydantoin, 21%
borax and Lowe sodium Stewart:
. ,
able 111
wreak Tablet
Run Force Tablets/ Wt. Thickness Strength density
No. (tons) minute (em.) (in.) (lobs.) go
8 6 - 10.2 0.474 50-75 1.66
Tablets were made as above with 73~ bromochlorohydantoin, 26%
granular borax and Lowe sodium Stewart:
.'
, , ..
. .
.
. 0544H - 17 -
.
:. .
12~082S
Table IV
Break Tablet
Run Force Tablets/ We. Thickness Strength Density
Jo. (tons) minute my (in.) (lobs.) go . )
9 6 - 10.2 0.470 75-80 1.68
6 - 10.3 0.473 75-80 1.69
11 6 - 10.0 ~.462 42-55 1.67
12 6 - 10.0 0.470 90-95 1.65
The tablets of runs 8 to 12 had shiny sides, with little capping
or sticking.
The tablets made below contained 68% bromochlorohydantoin, 31%
granular borax and 1% sodium Stewart.
fable V
Break Tablet
Run Force Tablets/ Wt. Thickness Strength Density
No. tons) minute (em-) (in.) (lobs.) go
13 6 15 11.55 0.535 75-85 1.67
6 15 11.55 0.538 50-55 '1.66
16 6 20 11.65 ~.545 50-55 1.66
17 7 20 11.~ 0.54S 72-85 1.68
18 8 20 11.5 0.532 110 1.67
Jo Tablets of runs 13-18 showed some capping, but were generally
Jo satisfactory.
I
. EXAMPLE III
l ..
Two 10 gram tablets of the present invention were sealed within a
dispenser of the type shown in Fig. 1, and two 10 gram tablets were
sealed in a dispenser of the type shown in Fig. 2. All four tablets
comprised 68% bromochlorodimethylhydantoin, 31% borax, and 1% dummy
Stewart, and were 1 inch diameter and approximately 1/2 inch thick.
0544H - - 18 -
_ _
glue
The dispensers were suspended in separated toilet tanks, which were
flushed every hour for 16 hours over a 16 day period. readings of
available halogen level in the bowl water were recorded daily as shown
in Table VI.
Viable VI
Halogen (Pam)
Day Dispenser ox Figure 1 Dispenser of Figure 2
1 5.1 I
5.5 5.4
3 5.7 5.4
4 3.2 5.7
3.5 4.6
6 4.0 4.9
7 4.0 5.9
8 3.6 4.6
3.5 4.7
3.1 4,6
4.6
12 2.7 4.6
13 I 4.3
14 3.5 4.4
3.5
16 3.5 4.4
Average 3.7 5.1
'eye preferred embodiment of Fig. 2 delivered about 38% more
halogen then the embodiment ox oh dispensers, however,
delivered an effective amount of disinfectant to the bowl water.
0544H - 19 -
